Parking Lot LED Lighting Assessment Final Report - Emerging ...

Resource Conservation District
Greater San Diego County
Parking Lot LED
Lighting Assessment
Final Report
April 8 th , 2010

PREFACE
PROJECT TEAM
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Parking Lot LED Lighting Assessment
This project is sponsored by San Diego Gas & Electric’s (SDG&E®) Emerging Technologies Program (ETP)
with Jerine Ahmed as the project manager. Marty Leavitt, District Manager, was the contact and project
manager for Resource Conservation District. Daryl DeJean (daryl.eta@gmail.com) from Emerging
Technologies Associates, Inc. provided technical consulting, data analysis, overall coordination of all
parties involved, and finalized the report.
DISCLAIMER
This report was prepared as an account of work sponsored by San Diego Gas & Electric Company. While
this document is believed to contain correct information, neither SDG&E®, Emerging Technologies
Associates nor Resource Conservation District, nor any employees, associates, makes any warranty,
expressed or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of
any information, apparatus, product, or process disclosed, or represents that its use would not infringe
privately owned rights. References herein to any specific commercial product, process or service by its
trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its
endorsement, recommendation, or favoring by SDG&E®, Emerging Technologies Associates nor Resource
Conservation District, their employees, associates, officers and members. The ideas, views, opinions or
findings of authors expressed herein do not necessarily state or reflect those of SDG&E®, Emerging
Technologies Associates or Resource Conservation District. Such ideas, views, opinions or findings should
not be construed as an endorsement to the exclusion of others that may be suitable. The contents, in
whole or part, shall not be used for advertising or product endorsement purposes. Any reference to an
external hyperlink does not constitute an endorsement. Although efforts have been made to provide
complete and accurate information, the information should always be verified before it is used in any
way.
ACKNOWLEDGEMENTS
We would like to acknowledge Resource Conservation District and SDG&E® for their cooperation in the
project. Without their participation, this assessment project would not have been possible.

TABLE OF CONTENTS
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Parking Lot LED Lighting Assessment
Executive Summary ..................................................................................................................................................... 5
Introduction ................................................................................................................................................................ 6
Project Background ..................................................................................................................................................... 7
Project Overview ................................................................................................................................................. 7
Technological Overview ...................................................................................................................................... 7
Market Overview ................................................................................................................................................ 7
Project Objectives ....................................................................................................................................................... 9
Methodology ............................................................................................................................................................. 10
Host Site Information ........................................................................................................................................ 10
Measurement Plan ............................................................................................................................................ 10
Equipment ......................................................................................................................................................... 10
Electrical Demand and Energy Savings .............................................................................................................. 11
Lighting Performance ........................................................................................................................................ 11
Economic Performance ..................................................................................................................................... 11
Conclusion ................................................................................................................................................................. 14
Appendix A ................................................................................................................................................................ 15

Abbreviations and Acronyms
CCT Correlated Color Temperature
DOE Department of Energy
ETP Emerging Technologies Program
GWh Gigawatt Hour
HID High Intensity Discharge
HPS High Pressure Sodium
IESNA Illuminating Engineering Society of North America
kW Kilowatt
kWh Kilowatt Hour
LED Light Emitting Diode
MH Metal Halide
MWh Megawatt hour
SDG&E San Diego Gas & Electric
SSL Solid State Lighting
US United States
W Watt
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Parking Lot LED Lighting Assessment

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Parking Lot LED Lighting Assessment
List of Tables Page
Table 1: Demand and Energy Savings .......................................................................................................................... 5
Table 2: Simple Payback New Construction ................................................................................................................ 5
Table 3: Demand and Energy Savings ........................................................................................................................ 11
Table 4: Photopic Illuminance Results ....................................................................................................................... 11
Table 5: Energy Cost Savings with LEDs ..................................................................................................................... 12
Table 6: New Construction Simple Payback Based Upon Energy Savings .................................................................. 12
Table 7: New Construction Simple Payback Based Upon Energy and Annual Maintenance Savings with LEDs ........ 12

EXECUTIVE SUMMARY
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Parking Lot LED Lighting Assessment
San Diego Gas &Electric (SDG&E®) was interested in evaluating LED technology in parking lot applications.
Resource Conservation District agreed to participate in an assessment to determine the viability of an LED lighting
solution for their parking lot. The goal of the project was to determine the energy savings potential provided by
LED lighting as compared to the traditional high intensity discharge metal halide light source.
Resource Conservation District was selected as an ideal site for the project due to the size of the parking lot. With
only seven luminaires in the parking lot, the site allowed for a complete implementation of LED luminaires.
Additionally, this was a new installation requiring the pole and luminaire, not just a retrofit of the luminaire.
Quantitative light and electric power measurements were taken for the project. Electric energy and demand
savings per LED luminaire are shown in Table 1. Based upon the annual operating cost savings and installed cost of
an LED luminaire, the simple payback period for this new construction project is shown below in Table 2.
Parking Lot
(4165 Operating hours)
Table 1: Demand and Energy Savings
# of Units Power (W) Demand (kW) Reduction (%) Energy (kWh) Reduction (%)
250 W MH 7 291 2.0 - 8,484 -
135 W LED 7 139 1.0 52 4,053 52
Parking Lot
(4165 Operating hours)
Table 2: Simple Payback New Construction
# of Units
Product Cost
($)
Incremental Cost
($)
Annual Energy
Cost Savings ($)
Simple Payback
(years)
250 W MH 7 8,196 - - -
135 W LED 7 13,423 5,227 886 5.9
This assessment project will assist numerous facility managers and building owners across the country when
considering LED luminaires as an option for new lighting installations in parking lots meeting their energy efficiency
as well as safety and security needs. Local site requirements, luminaire quality, as well as economic considerations
may directly impact the outcome of similar assessment projects. Therefore, readers are advised that each
installation is unique. It is recommended the reader exercise due diligence in selecting luminaires specific to
their needs. The results of this project corroborate similar studies, specifically those conducted by Pacific Gas &
Electric (www.etcc-ca.com).
Based upon the findings of this project, and LED technologies potential, it is recommended that future projects
consider the following:
evaluating the benefits and acceptability of bi-level or adaptive lighting
determination of the impact of LED lighting on security cameras and their ability to clearly
depict images in the parking lot

INTRODUCTION
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Parking Lot LED Lighting Assessment
In response to an overwhelming interest in innovations in LED lighting technology for the outdoor area lighting
applications, San Diego Gas & Electric’s Emerging Technologies Program conducted this assessment with the
following objectives:
identify potential LED solution for outdoor area lighting, specifically for parking lots
assess LED lighting technologies, validating manufacturer’s claims regarding energy savings, light levels
and light characteristics
During early 2009, Resource Conservation District, located in Lakeside, California began considering options for
their outdoor area lighting needs. The build out of their new office space allowed for the opportunity to include
new parking lot lighting. In lieu of replacing dysfunctional poles and fixtures with traditional metal halide fixtures,
LEDs were the light source of choice. The construction was completed in July 2009.

PROJECT BACKGROUND
Project Overview
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Parking Lot LED Lighting Assessment
The Parking Lot LED Lighting Technology Assessment project was conducted as part of the Emerging Technologies
Program of San Diego Gas & Electric Company (SDG&E®). The Emerging Technologies Program “is an informationonly
program that seeks to accelerate the introduction of innovative energy efficient technologies, applications
and analytical tools that are not widely adopted in California. The information includes verified energy savings and
demand reductions, market potential and market barriers, incremental cost, and the technology’s life expectancy.”
Emerging Technologies Associates, Inc. was retained by SDG&E® to manage the Parking Lot LED Lighting
Technology Assessment project, develop project methodology, coordinate the participants and stakeholders and
conduct the data collection and analysis for the project.
The Parking Lot LED Lighting Technology Assessment project studied the applicability of light emitting diodes
(LEDs) in a parking lot application. At Resource Conservation District, the seven parking lot lights which were
planned to be metal halide were replaced with an LED luminaire. The specification required a different pole and
luminaire than originally planned. The applicability of the technology was determined by light output and power
usage and economic factors.
Technological Overview
At the time of this assessment, LED lighting in outdoor area lighting applications such as parking lots was gaining
momentum because of the light source’s ability to provide the required surface illuminance with improved
uniformity and longer life using less energy than traditional light sources. The advancement of LED technology
since the advent of white LED’s presents some significant opportunities in outdoor area lighting which includes
parking lots. “LED technology is rapidly becoming competitive with high-intensity discharge (HID) light sources for
outdoor area lighting” (source: www.netl.doe.gov/ssl DOE SSL LED Application Series: Outdoor Area Lighting).
The most common light sources utilized to illuminate outdoor areas including streets, roadways, parking lots,
parking structures and pedestrian areas are metal halide (MH) and high pressure sodium (HPS). The performance
of these light sources is well documented with regard to lamp life and light characteristics. It is believed that a
well-designed LED outdoor luminaire can provide at least comparable light characteristics as the traditional high
intensity discharge light sources in an efficient manner (source: www.netl.doe.gov/ssl DOE SSL LED Application Series:
Outdoor Area Lighting).
The US Department of Energy (DOE) reports that LED technology is changing at a rapid pace. Overall, the
performance of LED technology is quickly gaining efficiency but the cost remains a barrier to market entry.
However, it should be noted that the costs for LED technology seems to be getting more competitive in the market
place with each year that passes and technological advances are reaching outdoor area lighting applications.
Market Overview
The development of LEDs for the outdoor area lighting niche represents a major breakthrough in energy efficiency
advancement. This parking lot application normally (66%) involves high wattage high intensity discharge (HID)
fixtures. The HID installed base of 3.1 million parking lot/garage/structure luminaires nationally. Currently, the
market penetration of LEDs in this sector is estimated at 0% because LED products for this application have only
recently become available. Further market penetration is expected to increase, as lamp efficacy rises. 1
1 Navigant Consulting, Inc. (2008). “Savings Estimates of Light Emitting Diodes in Niche Lighting
Applications.”

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Parking Lot LED Lighting Assessment
Additionally, decreasing cost and increasing customer confidence in the quality and life expectancy will further
reduce barriers to market adoption.
California represents approximately 8.4% of the total energy consumption in the US. (source:
http://tonto.eia.doe.gov/state/state_energy_profiles.cfm?sid=CA). Applying this 8.4% to the installed base of parking
lot/garage lighting fixtures of 3.1 million units results in California having an estimated installed base of 260,400 of
such fixtures. Assuming SDG&E® service territory equates to approximately 7% of California’s total installed base
(based upon statistics located at http://www.ecdms.energy.ca.gov/elecbyplan.aspx data found in Appendix B), it is
estimated that SDG&E® has an installed base of 18,228 parking lot/garage/structure fixtures in its service territory.
100% market penetration would equate to approximately 130 GWh reduction in electricity use. Realistically,
market penetration will most likely not ramp up until the high first cost barrier of LED luminaires is overcome.
Assuming 0.5% market penetration each year would result in an electricity savings of approximately 650 MWh
annually in SDG&E® service territory. This translates into 156.2 kW of reduced demand using 4165 annual
operating hours (assumed to be equal to hours stated in street light LS-2 Rate) for outdoor area lighting in SDG&E®
service territory.

PROJECT OBJECTIVES
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Parking Lot LED Lighting Assessment
The objectives of this project were to examine electrical, lighting, and economics of LED lighting technology in an
outdoor area application, specifically a parking lot, as compared to the traditional light source of metal halide
(MH). The potential electrical demand and energy savings were measured in terms of instantaneous system
wattage. The parking lot operates 4165 hours annually (based upon SDG&E’s LS-2 Rate). Lighting performance was
measured in terms of illuminance and Correlated Color Temperature (CCT) measured in Kelvin. Finally, since this
was a new installation the economic performance was calculated using the simple-payback for a new construction
project.

METHODOLOGY
Host Site Information
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Parking Lot LED Lighting Assessment
Resource Conservation District is a public service organization providing services throughout San Diego County.
The location is the regional office providing office space for approximately 15 personnel.
Resource Conservation District’s parking lot lighting was specified to be metal halide. The parking lot was to be lit
by seven 250 W (nominal) metal halide (MH) fixtures. The parking lot is not a homogeneous area, meaning there is
a small row of parking off the main entrance roadway, a small lot behind the front office building and another area
near their warehouse building. The fixtures are mounted at a height of 18 - 24 feet with no real pattern of spacing
between fixtures. The lights operate 4165 hours annually. The area does not have a surveillance camera. The
customer’s blended electric cost is $0.20 per kWh.
Measurement Plan
A measurement plan was developed to measure the lighting performance of each luminaire. Pre installation
lighting characteristics, power and energy is based upon manufacturer data for a 250 watt metal halide system. A
data point grid was used to collect the illuminance for each light source. The Correlated Color Temperature was
recorded at each data point as well. Instantaneous electrical power data for each luminaire was collected utilizing
a Fluke meter.
Equipment
The following equipment was used to collect the light and power characteristic data.
Illuminance and Correlated Color Temperature Meter: Power reading:
Konica Minolta Chroma Meter, Model CL-500 Fluke 322 meter
Accuracy: +- 2.0%
http://www.konicaminolta.com/sensingusa/products/Light-Measurement http://www.fluke.com

PROJECT RESULTS AND DISCUSSION
Electrical Demand and Energy Savings
Parking Lot LED Lighting Assessment
The parking lot lighting consisted of seven 250 W metal halide (MH) fixtures. Based upon industry technical data,
each MH fixture, consisting of the lamp and ballast, consumes 291 W. The new LED luminaire was stated as 135 W.
This results in the LED luminaire using 52% less demand than the MH fixtures. Taking into account all seven
fixtures in the parking lot, the annual reduction of energy usage is 18,396 kWh or 52% less as shown in Table 3.
Parking Lot
(4165 Operating hours)
Table 3: Demand and Energy Savings
# of Units Power (W) Demand (kW) Reduction (%) Energy (kWh) Reduction (%)
250 W MH 7 291 2.0 - 8,484 -
135 W LED 7 139 1.0 52 4,053 52
Lighting Performance
For the assessment area, photopic illuminance and Correlated Color Temperature readings were taken. The focus
of this section is on the parking area off the main entrance roadway. Photopic illuminance measurements were
taken over a 175’ X 40’ area covering the one traffic lane and the parking stalls.
Illuminance levels were measured on a 10’ X 10’ grid. The maximum and minimum illuminance levels were
determined from all measurements. The ratio of these two values is known as the uniformity ratio. The
Illuminating Engineering Society of North America recommends a minimum light level of one foot-candle and a
maximum uniformity ratio for parking lot of 10:1. Table 4 contains the photopic illuminance data and uniformity
ratios. It is evident that neither light source meets IESNA requirements in terms of maximum uniformity ratio or
minimum light level. While the LED setup appears worse than the MH setup by IESNA numbers, in reality the LEDlit
parking lot “feels” a lot brighter than the MH setup, and appears perfectly fine in terms of light distribution and
light quality. It was not in the scope of this study to determine from parking lot users or facility management
whether they were satisfied with light levels and light quality.
Luminaire
Grid Points
Illuminated
(%)
Table 4: Photopic Illuminance Results
Average
Illuminance
(fc)
Max
Illuminance
(fc)
Min
Illuminance
(fc)
Average-to-
Minimum
Uniformity
Maximumto-
Minimum
Uniformity
MH 100 1.08 5.04 0.05 22:1 101:1 3,860
LED 100 5.52 21.15 0.13 31:1 163:1 6,280
Economic Performance
It is important to note that the cost and equipment assumptions made in this section apply only to Resource
Conservation District. Resource Conservation District was assessing their selection of LED luminaires in lieu of
high wattage high intensity discharge (HID) metal halide (MH) light sources. Therefore readers should consider
their specific variables such as maintenance, energy, luminaire/lamp costs and type of light distribution before
drawing any conclusions about the cost effectiveness of LED luminaires. For LED luminaires, luminaire/lamp
lifetime is a function of all components of the luminaire (LEDs, driver, housing, coatings, etc.), electrical and
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CCT

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Parking Lot LED Lighting Assessment
thermal properties. Therefore, manufacturer claims, with regard to the aforementioned factors, are highly
variable. Although the manufacturer data states 60,000 hours, the assumptions for LED life expectancy in this
project is based upon 50,000 hours as per the United States Department of Energy website (source:
http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/lifetime_white_leds.pdf).
1. Energy Cost Estimates
The energy cost is based upon the Resource Conservation District’s blended rate of $0.20 per kWh. Resource
Conservation District’s parking lot lights operate 4165 hours annually. Table 5 provides the energy cost and savings
estimate assuming all seven fixtures in the parking were converted from the base case metal halide to the new LED
luminaires.
Parking Lot
(4165 Operating hours)
Table 5: Energy Cost Savings with LEDs
# of Units Power (W) Energy (kWh)
Annual Energy
Cost ($)
Annual Energy
Cost Savings
($)
Reduction (%)
250 W MH 7 291 8,484 1,697 - -
135 W LED 7 139 4,053 811 886 52
2. Payback Analysis
The simple payback calculations for the new construction scenario considered the total investment cost and energy
savings for the LED. In this project, the LED simple paybacks are shown in tables 7. Table 8 provides the
maintenance savings derived based upon the costs provided by Resource Conservation District.
Parking Lot
(4165 Operating hours)
Table 6: New Construction Simple Payback Based Upon Energy Savings
# of Units
Product Cost
($)
Incremental Cost
($)
Annual Energy
Cost Savings ($)
Simple Payback
(years)
250 W MH 7 8,196 - - -
135 W LED 7 13,423 5,227 886 5.9
Table 7: New Construction Simple Payback Based Upon Energy and Annual Maintenance Savings with LEDs
Parking Lot
(4165 Operating hours)
# of
Units
Incremental
Cost ($)
Annual
Maintenance
Cost ($)
Annual
Maintenance
Cost Savings
($)
Annual
Energy Cost
Savings ($)
Total
Annual
Savings
($)
250 W MH 7 - 8,484 1,697 - - -
135 W LED 7 5,227 4,053 4,431 886 5,317 1.0
The disposal fees were obtained from City of San Diego Environmental Services Department. To derive annual
maintenance cost savings, the total maintenance cost was divided by the life expectancy of the light source.
Payback
(years)
3. Luminaires and Lamp Life
This report uses 50,000 hours as the LED life expectancy, per the DOE website (source:
http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/lifetime_white_leds.pdf). The manufacturer of the
LED luminaires assessed in this project claim life expectancies greater than 50,000 hours. James Brodrick, Lighting

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Parking Lot LED Lighting Assessment
Program Manager, U.S. Department of Energy, Building Technologies Program, in a recent article entitled “Lifetime
Concerns”, when discussing how best to define the longevity of LED luminaires stated: “That’s not a simple matter,
because it doesn’t just involve the LED themselves, but rather encompasses the entire system-including the power
supply or driver, the electrical components, various optical components and the fixture housing.”
In this project, the LED life is approximately 12 years. This results in the payback being achieved at approximately
one half of the LED life, making this scenario an attractive alternative. This is an optimistic statement due to the
unproven life of LED products and does not indicate that LEDs are necessarily a viable option for all similar
situations.
Actual performance data documenting the life of LED luminaires does not yet exist due to the relative infancy of
LED technology for general illumination applications such as parking structure lighting. While LED technology
appears to be a viable option for parking lot lighting, LED product quality can vary significantly among
manufacturers. Therefore, it is recommended that readers exercise due diligence when selecting LED technology
for any application. Readers should also be aware that LED life and lighting performance are dependent upon
proper thermal and electrical design. Without the latter, premature failure may occur. Readers must properly
assess the potential risk associated with LED technology which has not undergone proper testing (i.e. LM 79, LM
80). The DOE LED Application Series: Outdoor Area Lighting Fact Sheet contains Design and Specifications
Considerations: http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/outdoor_area_lighting.pdf
4. Life Cycle Cost Analysis
Even though life cycle cost analysis was not part of the scope of this project, a full life cycle cost analysis is
recommended. There are many variables and considerations which are specific to each reader’s situation. It is
recommended that variables such as labor, cost of materials, maintenance practices, cost of financing, inflation,
energy rates, material cost, product life, etc. be determined for the specific project under evaluation.
Due to the uncertainty as to future labor, product and other costs, especially for LED technology, readers are
recommended to use their judgment and do their own due diligence regarding the future costs. Due to the rapid
advancements in LED technology, the pricing of the products may be reduced. Readers are encouraged to obtain
current price quotes for LED luminaires as the LED market is in a state of flux. Furthermore, each project’s
economic analysis will yield its unique set of results depending upon the project sponsors and site requirements.

CONCLUSION
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Parking Lot LED Lighting Assessment
This assessment project demonstrated that properly designed LED luminaires can provide energy savings up to
52% without compromising light characteristics required for parking lot applications.
A lesson learned during this assessment project is that there are many factors that may be unique and require
careful consideration. Each reader should consider their capital budgeting needs, maintenance and installation, as
well as any internal lighting standards. While the results of this assessment indicate significant energy savings
potential when LED luminaires replace high intensity discharge (HID) metal halide (MH) lighting, readers are
encouraged to complete a life cycle cost analysis to gain the complete economic picture of a technological change
out.
While the results of this project attest to the leaps in technological enhancements of LED lighting technology, the
high first cost required to retrofit outdoor lighting applications including parking lots with LEDs will be the main
barrier to significant market adoption. When using 50,000 hours as the expected life of the LED luminaire, the
significant energy savings and reduced maintenance costs do not adequately offset this high initial first cost in a
retrofit application. However, as illustrated by this project, LEDs may be a viable option in a new construction
application. Performance of LEDs combined with growing market acceptance of their higher performance versus
traditional outdoor area light sources may provide early adopters the impetus to invest in the emerging
technology.
Based upon the findings of this project, and LED technologies potential, it is recommended that future projects
consider the following:
evaluating the benefits and acceptability of bi-level or adaptive lighting
determination of the impact of LED lighting on security cameras and their ability to clearly
depict images in the parking lot

APPENDIX A
SDG&E® Market Potential Calculations Reference
California Electricity Statistics & Data
http://www.ecdms.energy.ca.gov/elecbyplan.aspx
Electricity Consumption by Planning Area
Planning Area Description Year Total Usage
Burbank, Glendale, and Pasadena 2007 4155.237028
Dept. of Water Resources 2007 9956.406553
Imperial Irrigation District 2007 3563.224165
Los Angeles Department of Water 2007 25258.28371
Other 2007 1709.525015
Pacific Gas and Electric 2007 107987.2289
Sacramento Municipal Utility District 2007 10917.07883
San Diego Gas & Electric 2007 20492.55364
Southern California Edison 2007 100470.2711
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Parking Lot LED Lighting Assessment
TOTAL 284509.8089
SDG&E % 7.202758216